A wireless distributed base station system adopts split-structured design of a radio remote unit (RRU) and a baseband processing unit (BBU). Correspondingly, a base station antenna system may adopt design of an RRU integrated with an antenna. Antenna systems that meet this design requirement include an integrated antenna system and an active antenna system (AAS).
Currently, the AAS is widely applied in wireless distributed base stations because the active antenna system has a higher network performance gain than a passive antenna. An existing AAS is capable of implementing a performance gain of receiving two dual-band signals. As shown in FIG. 1, the existing AAS adopts two arrays of antennas, where each array of antenna and a set of transceiving unit (referred to as TRX) arrays form a single-band active antenna. Each array of antenna includes n antenna elements that have two polarization directions, each set of transceiving unit TRX arrays include 2m TRX transceiving units, and every m TRX transceiving units correspond to a polarization direction. Radio-frequency signals received by the n antenna elements in a same polarization direction are sent to m TRX transceiving units via a combining-splitting network, and the m TRX transceiving units send the received radio-frequency signals to a signal processing unit for processing, to implement receiving of one single-band signal. Each antenna element of each array of antenna has two polarization directions, so that receiving of two single-band signals can be implemented. The two arrays of antennas are capable of implementing receiving of two dual-band signals. However, with the expansion of uplink network performance of a base station, implementation of receiving only two signals cannot meet a requirement of the uplink network performance of the base station.